Molecular and Clinical Characterization of CCT2 Expression and Prognosis via Large-Scale Transcriptome Profile of Breast Cancer

Revisiting the chaperonin T-complex protein-1 ring complex in human health and disease: A proteostasis modulator and beyond

BACKGROUND

Disrupted protein homeostasis (proteostasis) has been demonstrated to facilitate the progression of various diseases. The cytosolic T-complex protein-1 ring complex (TRiC/CCT) was discovered to be a critical player in orchestrating proteostasis by folding eukaryotic proteins, guiding intracellular localisation and suppressing protein aggregation. Intensive investigations of TRiC/CCT in different fields have improved the understanding of its role and molecular mechanism in multiple physiological and pathological processes.

MAIN BODY

In this review, we embark on a journey through the dynamic protein folding cycle of TRiC/CCT, unraveling the intricate mechanisms of its substrate selection, recognition, and intriguing folding and assembly processes. In addition to discussing the critical role of TRiC/CCT in maintaining proteostasis, we detail its involvement in cell cycle regulation, apoptosis, autophagy, metabolic control, adaptive immunity and signal transduction processes. Furthermore, we meticulously catalogue a compendium of TRiC-associated diseases, such as neuropathies, cardiovascular diseases and various malignancies. Specifically, we report the roles and molecular mechanisms of TRiC/CCT in regulating cancer formation and progression. Finally, we discuss unresolved issues in TRiC/CCT research, highlighting the efforts required for translation to clinical applications, such as diagnosis and treatment.

CONCLUSION

This review aims to provide a comprehensive view of TRiC/CCT for researchers to inspire further investigations and explorations of potential translational possibilities.

Two-Dimensional-PAGE Coupled with nLC-MS/MS-Based Identification of Differentially Expressed Proteins and Tumorigenic Pathways in MCF7 Breast Cancer Cells Transfected for JTB Protein Silencing

The identification of new cancer-associated genes/proteins, the characterization of their expression variation, the interactomics-based assessment of differentially expressed genes/proteins (DEGs/DEPs), and understanding the tumorigenic pathways and biological processes involved in BC genesis and progression are necessary and possible by the rapid and recent advances in bioinformatics and molecular profiling strategies. Taking into account the opinion of other authors, as well as based on our own team's in vitro studies, we suggest that the human jumping translocation breakpoint (hJTB) protein might be considered as a tumor biomarker for BC and should be studied as a target for BC therapy. In this study, we identify DEPs, carcinogenic pathways, and biological processes associated with JTB silencing, using 2D-PAGE coupled with nano-liquid chromatography tandem mass spectrometry (nLC-MS/MS) proteomics applied to a MCF7 breast cancer cell line, for complementing and completing our previous results based on SDS-PAGE, as well as in-solution proteomics of MCF7 cells transfected for JTB downregulation. The functions of significant DEPs are analyzed using GSEA and KEGG analyses. Almost all DEPs exert pro-tumorigenic effects in the JTBlow condition, sustaining the tumor suppressive function of JTB. Thus, the identified DEPs are involved in several signaling and metabolic pathways that play pro-tumorigenic roles: EMT, ERK/MAPK, PI3K/AKT, Wnt/β-catenin, mTOR, C-MYC, NF-κB, IFN-γ and IFN-α responses, UPR, and glycolysis/gluconeogenesis. These pathways sustain cancer cell growth, adhesion, survival, proliferation, invasion, metastasis, resistance to apoptosis, tight junctions and cytoskeleton reorganization, the maintenance of stemness, metabolic reprogramming, survival in a hostile environment, and sustain a poor clinical outcome. In conclusion, JTB silencing might increase the neoplastic phenotype and behavior of the MCF7 BC cell line. The data is available via ProteomeXchange with the identifier PXD046265.

A potential tumor marker: Chaperonin containing TCP‑1 controls the development of malignant tumors (Review)

Due to concealment, high invasiveness and a lack of indicators, malignant tumors have emerged as one of the deadliest diseases worldwide and their incidence is rising yearly. Research has revealed that the chaperonin family member, chaperonin containing TCP‑1 (CCT), serves a crucial role in malignant tumors. CCT is involved in the growth of numerous malignant tumors such as lung cancer, breast cancer, hepatocellular carcinoma and colorectal cancer and assists the folding of a number of proteins linked to cancer, such as KRAS, p53 and STAT3. According to clinical data, CCT is highly expressed in a range of tumor cells and is associated with poor patient prognosis. In addition, through controlling the cell cycle or interacting with other proteins (including YAP1, HoXB2 and SMAD2), CCT has an effect on the proliferation, invasion and migration of cancer cells. As a result, it is possible that CCT will become a new tumor marker or therapeutic target, which will provide some guidance for early tumor screening or late tumor prognosis. In the present review, the molecular properties of CCT are introduced, alongside a summary of its interactions with other cancer‑related proteins and a discussion of its function in common malignant tumors. It is expected that the present review will offer fresh approaches to the treatment of cancer.

Exploring breast cancer exosomes for novel biomarkers of potential diagnostic and prognostic importance

The comprehensive bioinformatics analysis of breast cancer exosomes revealed that HSP90AA1, CCT2, and ENO1 were novel hub genes in the giant protein-protein interaction network of 110 exosomal proteins. Exosomes and their cargo such as discrete proteins, nucleic acids, and lipids are having potential role in the pathophysiology of breast cancer (BC). This study showed that the identified hub genes were particularly abundant in GO and KEGG pathways relevant to the positive regulation of telomerase. In addition, these hub genes were found to be considerably overexpressed in breast adenocarcinoma patients compared to healthy controls, and further, this overexpression is linked to the poor prognosis in BC patients. Furthermore, the ROC analysis revealed that CCT2 gene has strong diagnostic and prognostic value for BC. Additionally, this in silico analysis found that the anticancer agents and HSP90 inhibitors such as ganetespib, retaspimycin, and tanespimycin would have considerable potential in the treatment of BC. Overall, this study findings imply that HSP90AA1, a molecular chaperon and CCT2, a chaperonin would serve as diagnostic and prognostic biomarkers, respectively, for BC. However, these findings need to be further confirmed by laboratory and clinical studies for validating their potential applications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03422-w.

Comprehensive prognostic and immunological analysis of CCT2 in pan-cancer

CCT2 acts as a molecular chaperone protein that assists in the proper folding of proteins, thus ensuring a dynamic balance of cellular homeostasis. Despite increasing evidence supporting the important role of CCT2 in the tumorigenesis of certain cancers, few articles that provide a systematic pan-cancer analysis of CCT2 have been published. Hence, to evaluate the expression status and prognostic significance of CCT2 in pan-cancers, an analysis of the relationship between CCT2 and different tumor immune cell infiltrations was conducted using datasets from the Cancer Genome Atlas, Cancer Cell Lineage Encyclopedia, and so on. In most cancers, CCT2 expression was high and was associated with poor prognosis. Moreover, CCT2 gene expression was negatively correlated with infiltration of most immune cells in 10 cancer types, and CCT2 expression was related to tumor mutation burden and microsatellite instability. The role that CCT2 plays in tumorigenesis and tumor immunity suggests that it can serve as a prognostic marker in many cancers.

The Chaperone System in Breast Cancer: Roles and Therapeutic Prospects of the Molecular Chaperones Hsp27, Hsp60, Hsp70, and Hsp90

Breast cancer (BC) is a major public health problem, with key pieces of information needed for developing preventive and curative measures still missing. For example, the participation of the chaperone system (CS) in carcinogenesis and anti-cancer responses is poorly understood, although it can be predicted to be a crucial factor in these mechanisms. The chief components of the CS are the molecular chaperones, and here we discuss four of them, Hsp27, Hsp60, Hsp70, and Hsp90, focusing on their pro-carcinogenic roles in BC and potential for developing anti-BC therapies. These chaperones can be targets of negative chaperonotherapy, namely the elimination/blocking/inhibition of the chaperone(s) functioning in favor of BC, using, for instance, Hsp inhibitors. The chaperones can also be employed in immunotherapy against BC as adjuvants, together with BC antigens. Extracellular vesicles (EVs) in BC diagnosis and management are also briefly discussed, considering their potential as easily accessible carriers of biomarkers and as shippers of anti-cancer agents amenable to manipulation and controlled delivery. The data surveyed from many laboratories reveal that, to enhance the understanding of the role of the CS in BS pathogenesis, one must consider the CS as a physiological system, encompassing diverse members throughout the body and interacting with the ubiquitin–proteasome system, the chaperone-mediated autophagy machinery, and the immune system (IS). An integrated view of the CS, including its functional partners and considering its highly dynamic nature with EVs transporting CS components to reach all the cell compartments in which they are needed, opens as yet unexplored pathways leading to carcinogenesis that are amenable to interference by anti-cancer treatments centered on CS components, such as the molecular chaperones.

The TRiCky Business of Protein Folding in Health and Disease

Maintenance of the cellular proteome or proteostasis is an essential process that when deregulated leads to diseases like neurological disorders and cancer. Central to proteostasis are the molecular chaperones that fold proteins into functional 3-dimensional (3D) shapes and prevent protein aggregation. Chaperonins, a family of chaperones found in all lineages of organisms, are efficient machines that fold proteins within central cavities. The eukaryotic Chaperonin Containing TCP1 (CCT), also known as Tailless complex polypeptide 1 (TCP-1) Ring Complex (TRiC), is a multi-subunit molecular complex that folds the obligate substrates, actin, and tubulin. But more than folding cytoskeletal proteins, CCT differs from most chaperones in its ability to fold proteins larger than its central folding chamber and in a sequential manner that enables it to tackle proteins with complex topologies or very large proteins and complexes. Unique features of CCT include an asymmetry of charges and ATP affinities across the eight subunits that form the hetero-oligomeric complex. Variable substrate binding capacities endow CCT with a plasticity that developed as the chaperonin evolved with eukaryotes and acquired functional capacity in the densely packed intracellular environment. Given the decades of discovery on the structure and function of CCT, much remains unknown such as the scope of its interactome. New findings on the role of CCT in disease, and potential for diagnostic and therapeutic uses, heighten the need to better understand the function of this essential molecular chaperone. Clues as to how CCT causes cancer or neurological disorders lie in the early studies of the chaperonin that form a foundational knowledgebase. In this review, we span the decades of CCT discoveries to provide critical context to the continued research on the diverse capacities in health and disease of this essential protein-folding complex.

Chaperonins in cancer: Expression, function, and migration in extracellular vesicles

The chaperonins CCT and Hsp60 are molecular chaperones, members of the chaperone system (CS). Chaperones are cytoprotective but if abnormal in quantity or quality they may cause diseases, the chaperonopathies. Here, recent advances in the understanding of CCT and Hsp60 in cancerology are briefly discussed, focusing on breast and brain cancers. CCT subunits, particularly CCT2, were increased in breast cancer cells and this correlated with tumor progression. Experimental induction of CCT2 increase was accompanied by an increase of CCT3, 4, and 5, providing another evidence for the interconnection between the members of the CS and the difficulties expected while manipulating one member with therapeutic purposes. Another in silico study demonstrated a direct correlation between the increase in the tumor tissue of the mRNA levels of all CCT subunits, except CCTB6, with bad prognosis. Studies with glioblastomas demonstrated an increase in the CCT subunits in the tumor tissue and in extracellular vesicles (EVs) derived from them. Expression levels of CCT1, 2, 6A, and 7 were the most increased and markers of bad prognosis, particularly CCT6A. A method for measuring Hsp60 and related miRNA in exosomes from blood of patients with glioblastomas or other brain tumors was discussed, and the results indicate that the triad Hsp60-related miRNAs-exosomes has potential regarding diagnosis and patient monitoring. All these data provide a strong foundation for future studies on the role played by chaperonins in carcinogenesis and for fully developing their theranostics applications along with exosomes.